The jig this year has been a great early season presentation for me. I have received a bunch of emails from people asking questions about how to fish the jig for trout. The jig can be a very productive presentation or a extremely frustrating experience. This early season has been a bit cooler than the past couple of years and we received 70+ inches of snow over the winter. With the cooler water temperatures the fish haven't been too active, thus avoiding chasing down faster moving presentations such as spinners, spoons or hard baits. The trout will still hit those baits, but when the fish aren't biting and the water temperatures are still cool you should try a jig.
There are many factors in selecting a jig to fish. The biggest factor I was say would be the current strength. The faster the current the heavier the jig should be. When fishing for Wisconsin inland trout you shouldn't have to go any heavier than 1/4 oz. Unless you are fishing larger freestone rivers up north. Another huge factor is what is the bottom like? Rocky bottoms you might have to downsize again to avoid having the jig drop too fast into the rocks and becoming snagged. With a sand or soft bottom you can pretty much get away with any type of weight. When selecting a weight you should also consider what would look natural. If it sinks like a rock with no action you are using the wrong presentation. I like a jig that I can "walk" or "drag" a crossed the bottom or tick a crossed rocks to resemble a Crayfish, Leech or Minnow. Having a good feel is very important also, it can take awhile to tell the difference between hitting the top of a boulder or a fish taking the jig. If you have ever walleye fished or bass fished with a jig it is pretty similar, but you are using lighter line and rod so you should have better sensitivity.
Check your line often and make sure the line doesn't have small cuts or abrasions. You are fishing down in the cover which can chew away line pretty easy. I use my mouth to feel for the abrasions rather than just your fingers.
White, Brown, Black and Pumpkin Seed are the colors that I prefer. I use 2-3 inch grub tails, curly tails or double tailed jigs.
When a fish takes the jig I try not to set the hook right away, but I will drop my rod tip down reel up once than set the hook. Trout will often times grab the jig and carry it for awhile since it feels and smells like a real meal. This will make sure the trout has the hook in it's mouth and not just grabbing the tail.